Here is why I think plastic material used in sliders and slider housing is important. I mentioned in a previous post(
see here), but didn't post the actual chart.
Here it is.
Original chart from Dupont document
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The same chart replicated in Excel to get numbers below
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Wear rate (reference2)
ABS: approx. 700
PBT: approx. 40
POM: approx. 12
Note - This figure has been approximated from a chart in reference2.
Coefficient of friction (reference2)
ABS: approx. 0.35
PBT: approx. 0.25
POM: approx. 0.21
Note - This figure has been approximated from a chart in reference2.
reference2 :
http://plastics.dupont.com/plastics/pdflit/europe/delrin/DELLWLFe.pdf
This is why ABS plastic is not recommended where friction is of concern.
Here are what I find on different switches:
1. HHKB: HHKB housing is made of ABS plastic and the housing acts as slider housing. Topre switch's slider is not ABS, it seems to me they are pretty similar to POM and coated with some kind of lubricant out of factory.
2. Membrane keyboards: Pretty much all membrane keyboards have ABS plastic housing and sliders.
3. Cherry: Cherry switches' slider housing use PBT(saw this at Cherry wiki) and sliders seems to be some sort of slick plastic(I am guessing they are either POM or PBT, but certainly not ABS because they do not react to acetone.)
4. Alps:Alps switches' slider housing is made from ABS. Again, not sure about slider but certainly not ABS.
5. What about realforce? -- This is my question.
side note: I compared sliders of Cherry Reds and Browns, and it seems browns have more slick surface. (I scratched surface with my finger nail to compare) I am suspecting that the slider material has changed over time. I heard sliding surface of Cherry blacks are similar to that of browns. This is why many Korean keyboard enthusiasts mod blacks and swap springs (they use custom springs), and avoid red sliders for their mods.
I do not have enough information to conclude that there is causal relationship between the material used and durability, but I am pretty certain that there is strong correlation between the two. Membrane keyboards develop friction quite quickly. Alps switches are said to be not so durable. Topre switches have shorter life than Cherries(it may be in part due to rubbers too). Cherry switches have longest life thanks to more slick and durable material used.